1256704811 has 2 divisors, whose sum is σ = 1256704812. Its totient is φ = 1256704810.

The previous prime is 1256704789. The next prime is 1256704819. The reversal of 1256704811 is 1184076521.

It is a strong prime.

It is an emirp because it is prime and its reverse (1184076521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1256704811 - 2⁶ = 1256704747 is a prime.

It is not a weakly prime, because it can be changed into another prime (1256704819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628352405 + 628352406.

It is an arithmetic number, because the mean of its divisors is an integer number (628352406).

Almost surely, 2^1256704811 is an apocalyptic number.

1256704811 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256704811 is an equidigital number, since it uses as much as digits as its factorization.

1256704811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13440, while the sum is 35.

The square root of 1256704811 is about 35450.0325951895. The cubic root of 1256704811 is about 1079.1399219528.

The spelling of 1256704811 in words is "one billion, two hundred fifty-six million, seven hundred four thousand, eight hundred eleven".